1. Field of the Invention
The present invention relates to an apparatus for removing dental appliances bonded to multiple teeth and a method for using the same. More specifically, the present invention relates to an apparatus for removing bonded dental appliances having a stationary hook and a unique platform to engage the flat surface of the acrylic covering the teeth.
2. Brief Description of the Background Art
Orthodontics appliances, also known as acrylic onlays, are either bonded or removable intra-oral devices which alter the posture of the maxilla and mandible (jaws) and the muscle forces against the teeth and the crano-facial skeleton. These devices are molded to fit the patient specific plaster or stone models of the patient's upper or lower teeth and dento-facial specifications and are placed in the mouth for a finite duration to dynamically alter the jaw's neuromuscular action thereby affecting bony growth and occlusal relationships.
In general, acrylic appliances are used for orthopedic correction, functional correction and disarticulation of the teeth and jaws. In orthopedic correction, also known as skeletal correction, the appliance functions to change the size and skeletal position of the jaws. In functional treatment, the appliance causes the jaw to close into a new position, thereby enabling the jaw to modify its growth and assume a new posture. This procedure is often used to permit the jaw to reposture and the temporomandibular joint to modify in order to improve facial/skeletal appearance and alleviate pain associated with TMD or Temporo-Mandibular Joint Disorders or Dysfunction. These applications have made acrylic appliances indispensable to dentistry.
The apparatus specific to this invention is used for removal of the bonded appliances. The advantage of the bonded appliances primarily relates to the elimination of patient compliance with wearing of the removable appliances and guarantees 24-hour per day functional change.
Because of their particular application, the ideal age for starting treatment is between the ages of three to 12 years. That is, the age where the cranial structure is still growing and could adapt to the new posture. The acrylics are bonded (cemented) to the teeth using an adhesive for a finite treatment period. The patient is unable to alter the position of the appliance until it is removed by the orthodontist. At the end of the treatment period the practitioner removes the acrylic appliance by breaking the bond and ideally recovering the appliance intact. Thereafter, the appliance may be used as a temporary onlay until a stabilizing plate or retainer is properly fitted to the patient. The retaining appliance may be worn for a shorter period of time (e.g., overnight) to supplement the treatment.
Removing the bonded acrylic has been a source of great distress and some discomfort to the patients and especially to the younger patients. Also, because the appliance is often used as a temporary onlay after it is removed, its intact preservation during the removal stage is a source of distress to the practitioners who must not fracture or otherwise damage the appliance during removal. Patient comfort and reducing the time taken to remove the appliance are important factors. In addition, removing the appliance without causing laceration of the gingival tissue is important to both the patient and the practitioner. Finally, because of the above-stated factors, orthodontists are reluctant to relegate this seemingly routine task to dental auxiliaries.
Although various devices for extracting tooth or synthetic onlays such as caps and bridges have been proposed, none addresses the particular problems associated with removing acrylic appliances. For example, U.S. Pat. No. 354,863 discloses a pair of dental forceps for extracting roots of teeth. The extraction device comprises a pair of pivotally connected arms that form the jaws of the forceps at one end, and the arms of the forceps at the other end. The jaws include a convex-shaped metal disc that is rotatably connected to the forceps by a ball joint, and a beak that sits perpendicular to the face of the metal disc. The beak has a hallow-ground center enabling it to fit upon the root of the tooth. This device is not suitable for removing acrylic appliances. Particularly, the convex shape of the metal disc prevents a snug bracing of the acrylic surface. Instead, it would concentrate the force exerted by the forceps in a relatively small area which could cause fracture of the appliance. In addition, the sharp narrow beak would create a very small contact area with the acrylic that could also fracture the appliance.
U.S. Pat. No. 1,628,499 discloses a device for tooth extraction. The device comprises a scissors-like forceps having as a first jaw a pivotally mounted rubber-covered disc adapted to rest against the gum, and a second jaw that impinges on the back face of the tooth. The second jaw is described as having a shank which connects to the jaw at one end and forms a concave angular recess which converges to a pointed tip at the other end. The concave recess allows for the device to come close to the cusp of the tooth while not making contact therewith. In practice, the device is used by placing the rubber-covered disc against the outer gum and impinging the upper pointed tip of the shank against the inner surface of the tooth. This device is also not suitable for removing an acrylic onlay because the pointed tip does not allow for a proper gripping of the acrylic. Instead, it would cause bleeding as the beak would cut against the gingival tissues. Moreover, the pointed tip of the beak is designed for securing and extracting teeth and it would not establish a proper grip on the acrylic. As with the Hughes patent, this device would also fracture the appliance.
U.S. Pat. No. 3,755,902 to Northcutt discloses a tool for removing a very small orthodontic onlay which has been cemented to the tooth. Northcutt's device comprises a pair of scissors-like jaws connected to a lever. The upper jaws have forward-intruding portion which goes behind the onlays surface to separate the onlay from the tooth surface. The lower jaw comprises a stationary pad enabling the edge of the tooth to rest thereon. This device is also not suitable for removing acrylic onlay because it would be uncomfortable to the patient, endanger both the tooth enamel and structure and could severely lacerate the gingival tissues.
Two of the above structures are variations of a dental forceps designed for extracting teeth. Because they are designed to fit a human structure and remove a tooth, they do not lend themselves to non-destructive removal of acrylic appliances. The third for debonding very small (less than 4.0 mm) attachments bonded to individual teeth. Therefore, it is desirable to provide a simple device for debonding an acrylic appliance wherein the device is capable of non-destructive removal of the appliance with minimal trauma and injury to patient.